Method and an apparatus for monitoring the amount of erosion in the waring parts of a crusher

ABSTRACT

A method and apparatus are disclosed for monitoring the amount of erosion in the wearing parts of a crusher, in which method the wearing of the crusher is provided with a wear sensor that issues a signal to the crusher&#39;s automatic control system as erosion in the wearing part reaches a predetermined depth. Upon receiving the signal, the control system initiates predetermined actions, such as an alarm, stopping the crusher and/or ordering of a spare part. Information on the amount of erosion in a wearing part is transmitted wirelessly to the automatic control system.

The invention relates to the monitoring of the amount of erosion in thewearing parts of crushers. More specifically, the invention relates tocrushers equipped with an automatic control system.

Wear monitoring of the wearing parts in a crusher is vital to avoid“wear-through” of a wearing part resulting in a considerably expensiveand time-consuming repair of the crusher as compared with a normalreplacement of the crusher's wearing part.

In patent publication U.S. Pat. No. 6,129,297 is disclosed one method ofmonitoring the progress of wear in the wearing parts of a crusher.According to this invention, on the rear surfaces of the wearing partsin the crusher are made recesses reaching up to a depth that representsthe maximum allowable degree of wear of the wearing parts in thecrusher. The recesses are filled with a suitable material such as acolor composition. When the erosion of the wearing parts eventuallyreaches a point that reveals the recesses, the color composition spreadsonto the surfaces of the wearing parts of the crusher, wherefrom thewear indication is easy to detect by the crusher operator. However, thiskind of arrangement fails to provide on-line wear information duringcrushing inasmuch as the crusher must always be stopped for inspectionthus causing losses in production capacity. Moreover, the amount oferosion can be monitored only by climbing onto the crusher, a task thatinvariably involves a risk of operator safety.

The present invention is based on equipping the wearing parts of acrusher with wear sensors that at the instant of the wearing partsreaching a given degree of wear deliver a signal to the crusher'sautomatic control system. Based on this signal, the automatic controlsystem issues an alarm and/or stops the crusher. The control system mayoptionally be complemented with an automatic ordering system of wearingparts, whereby setting the wear sensor to alarm at a predetermined wearthreshold, the automatic control system may launch a spare part order inorder to have the spare part available on-site when monitored wear partsof the crusher reach the end point of their service life requiring areplacement part.

More specifically, the method according to the invention ischaracterized by what is stated in the characterizing part of claim 1,and the apparatus according to the invention is characterized by what isstated in the characterizing part of claim 5.

In the following, the invention will be examined in more detail bymaking reference to the appended drawing in which

FIG. 1 shows a crusher control system according to the invention.

Referring to FIG. 1, therein is shown the adaptation of an apparatusaccording to the invention to the construction of a gyratory crusher 1.The wearing parts of the gyratory crusher, namely an inner liner 2 andan outer liner 3, are equipped with wear sensors 4, 5. The functions ofthe crusher are steered by an automatic control system 6 of the crusher.

In the illustrated exemplary embodiment, the wear sensors are embeddedat predetermined depths in the crusher liners. As the amount of erosionreaches the level of the sensors, the sensors either start to transmit asignal to the crusher's automatic control system that then performscertain preprogrammed functions or, alternatively, cease to send asignal, whereupon the control system after the lapse of a predetermineddelay performs the preprogrammed functions.

Upon receiving an alarm signal from the sensors, the automatic controlsystem may either forward the alarm to the crusher operator oralternatively automatically stop the crusher. In its simplest form, thecontrol system issues the alarm as a visual or acoustic signal. Thecontrol system may optionally be complemented with automatic routines ofspare part ordering, whereby the control system upon the receipt of thewear threshold signal issues the spare part order. To this end, the wearsensors must be embedded at a correct depth in the wearing parts suchthat the crusher operation can be continued using the old wearing partduring the delivery time of the new wearing part.

In its simplest form, the sensor embedded in the wearing part maycomprise a conductor loop surrounded by an insulating material. Hereby,an alarm is issued at the instant the loop is interrupted due to wear.Alternatively, the system may be equipped with other kinds of simpleon-off type switches or sensors.

The signal issued by a sensor embedded in a given wearing part may alsobe transmitted wirelessly to the exterior side of the crusher by meansof a separate transmitter connected to the sensor. Respectively, thecrusher's automatic control system must be equipped with a compatiblereceiver. By complementing the wear sensor with an integral powersupply, the compact sensor package can be either embedded entirely in awearing part of the crusher or, alternatively, adapted between thewearing part and the surface supporting the same, whereby allcomplications due to sensor wiring are avoided.

In the former case, the operating energy of the sensor can be delivered,for example, by a battery. The integrated sensor package may also beprovided with a piezoelectric device capable of generating electricalenergy. One useful type of self-contained energy source is a mechanicalconverter of kinetic-to-electrical energy such as is used inwristwatches, for instance. One further alternative way of generatingthe operating power of the sensor is energy capture by means of RFtechniques from an electromagnetic field surrounding the crusher.

In the prior art it has been conventional to use the crusher's controlsystem also for controlling both the material infeed machinery and thecrushed material discharge machinery. Now, the wear sensors can beconfigured to control the entire machinery system in such a fashionthat, e.g., at an alarm issued by a wear sensor, material infeed intothe crusher is stopped.

The invention may also be implemented by way of utilizing a plurality ofseparate wear sensors connected to the crusher control system so thatdifferent kinds of actions are initiated depending on the sensor of thesystem issuing an alarm. In this fashion, e.g., an amount of erosionreaching a predetermined depth first triggers a warning alarm ofexhausting wearing parts to the crusher operator. If the crusheroperator fails to respond to the warning and allows the amount oferosion to progress down to a second depth level, the control system maybe allocated to stop the crusher thus preventing operator negligencefrom causing damage to the crusher.

The invention is not limited to any given type of crusher, but insteadmay be adapted to all kinds of crushers equipped with wearing parts.

Further, the invention is not limited to the wear sensors of a giventype, but instead may utilize any type of sensor capable of monitoringthe amount of erosion in the wearing parts of crushers.

1. A method for monitoring the amount of erosion in the wearing parts ofa crusher, in which method the erosion of the wearing parts of a crusheris monitored by the crusher's automatic control system and, as erosionin the wearing parts reaches a predetermined depth, the control systeminitiates predetermined actions, which actions comprise issuing analarm, characterized in that information on the amount of erosion in awearing part of the crusher is transmitted wirelessly to the automaticcontrol system of the crusher and that the predetermined actions furthercomprise at least one of the following actions: stopping the crusher orstopping material infeed to the crusher or ordering a wearing part forthe crusher.
 2. The method of claim 1, characterized in that thepredetermined depth of erosion of the wearing parts is such that thecrusher operation can be continued using the old wearing part during thedelivery time of the new wearing part.
 3. The method of claim 1,characterized in that a plurality of separate wear sensors connected tothe crusher control system is utilized so that different kind of actionsare initiated depending on the sensor of the system issuing an alarm. 4.An apparatus for monitoring the amount of erosion in the wearing partsof a crusher, the apparatus comprising an automatic control system ofthe crusher, and at least one wear sensor mounted on the wearing part ofthe crusher, characterized in that said wear sensor is equipped withmeans for transmitting the measurement signal wirelessly to theautomatic control system of the crusher and with a self-contained energysource.
 5. The apparatus of claim 4, characterized in that theself-contained energy source comprises means for converting kineticenergy into electrical energy.
 6. The apparatus of claim 4,characterized in that the self-contained energy source comprises apiezoelectric device for generating electrical energy.
 7. The apparatusof claim 4, characterized in that the self-contained energy sourcecomprises means for capturing electrical energy from an electromagneticfield launched about the crusher.
 8. The apparatus of claim 4,characterized in that the wear sensor comprises a conductor embedded inan insulator.
 9. The apparatus of claim 5, characterized in that thewear sensor comprises a conductor embedded in an insulator.
 10. Themethod of claim 2, characterized in that a plurality of separate wearsensors connected to the crusher control system is utilized so thatdifferent kind of actions are initiated depending on the sensor of thesystem issuing an alarm.
 11. The apparatus of claim 5, characterized inthat the wear sensor comprises a conductor embedded in an insulator. 12.The apparatus of claim 6, characterized in that the wear sensorcomprises a conductor embedded in an insulator.
 13. The apparatus ofclaim 7, characterized in that the wear sensor comprises a conductorembedded in an insulator.
 14. The apparatus of claim 6, characterized inthat the wear sensor comprises a conductor embedded in an insulator. 15.The apparatus of claim 7, characterized in that the wear sensorcomprises a conductor embedded in an insulator.
 16. The apparatus ofclaim 8, characterized in that the wear sensor comprises a conductorembedded in an insulator.